Lens sheet having lens array formed in preselected areas and articles formed therefrom

ABSTRACT

A lens sheet having one or more lens arrays positioned in selected discrete areas. Each lens array includes a plurality of lenses, each having a width, a height, and a lens peak. The lens array is set below the planar surface of the lens sheet, such that lens array does not extend above the lens sheet. Furthermore, the lens array is completely bordered by or contained within planar portions of the lens sheet. One or more dimensional images are printed below each of the lens arrays, and/or one or more static images can be printed on the planar portions of the lens sheet.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 13/229,116filed Sep. 9, 2011, which claims the benefit of U.S. ProvisionalApplication No. 61/420,571 filed Dec. 7, 2010, U.S. ProvisionalApplication No. 61/438,536 filed Feb. 1, 2011, and U.S. ProvisionalApplication No. 61/480,845 filed Apr. 29, 2011, each of which isincorporated herein in its entirety by reference.

FIELD OF THE INVENTION

The invention relates generally to dimensional image display sheetsincluding a plastic film having an array of lenses in one or morepreselected areas of the film and an optional image(s) to be displayedon and/or through the array. More particularly, the invention relates toimage display sheets having a planar portion and a lens array positionedflush with or below the planar portion, and an optional printed image(s)that is viewable on and/or through the lens array.

BACKGROUND OF THE INVENTION

It is often desirable to impart visual effects such as threedimensionality or motion characteristics upon articles of consumableproducts and the like. Dimensional image display devices or sheets areused to create these desirable visual effects such as, for example, 3Deffects, magnification, animation, depth, morphing, flipping, hiddencodes or messages, and other such types of graphics. The dimensionalimage display sheets can be applied to or used as various articles aseye-catching promotional tools, advertising, branding, games, and thelike. Examples of articles can include, for example, sports cards, gamecards, containers, cups, cup inserts, wraps, and sleeves, packagingmaterials such as packaging boxes, wrappers, tubes such as toothpastetubes, envelopes, greeting cards, invitations, napkins, posters,business cards, fabrics and clothing, billboards, stickers, labels,badges, pens, magnets, postcards, identification or stored value cards,such as gift cards, credit cards, rewards cards, wall paper, folderssuch as pocket folders, media packaging such as DVD or CD covers, andany of a variety of articles.

Dimensional image display devices typically incorporate a printed imageproximate a lens sheet having a lens array thereon. The printed imagecan be either directly bonded or printed to the lens array, or printedon a separate substrate and laminated to the lens array. Image segmentsor elements are printed using high resolution, and precise registrationtechniques to form the overall image. One such printing techniqueincludes interlacing images, in which a composite of two or more imagesare interlaced with each other in individual slices or segments to formthe overall image that will be viewed through a lens array. Theinterlaced image is then configured or mapped so that each lens of thearray focuses on at least a portion of the interlaced image. Theinterlaced image is configured to accommodate both viewing distance andcurvature through the lens.

One type of dimensional imaging technology well-known in the artincludes lenticular image technology. Lenticular image technologyincludes a lenticular image, such as an interlaced image, in combinationwith a lenticular lens array. The lenticular lens array is formed from aweb or sheet including a plurality of substantially parallel elongatedcylindrical lenticules or lenses extending from one surface. The secondsurface is planar. Typically, the lenticular lens array is formed from aplastic material and can be formed from any of a variety of techniquesincluding casting, coating, embossing, extruding, and the like. Theinterlaced image can be printed directly on the planar second surface,or can be printed on a separate substrate and subsequently laminated tothe lenticular lens array by a clear adhesive, fusing, compressionlamination, or other similar techniques. Examples of lenticular imagetechnology can be found in U.S. Pat. No. 6,900,944 to Tomczyk; U.S. Pat.No. 6,424,467 to Goggins; and U.S. Pat. No. 7,359,120 to Raymond et al.,the disclosures of which are incorporated herein by reference.

Currently available methods can provide a lens sheet or lenticulatedsheet array, which can vary in thickness or caliper, for example, fromabout 10 mils to about 40 mils. The thickness of the extruded lenticularlens layer is suggested by the formula: r=C×f or r=[(n′−n)/n′]×f where ris the radius of curvature of a lenticular lens, C is a constant, f isthe focal length of optimal focus thickness for the plastic, n′ is theindex of refraction of the lens construction material, such as anextruded plastic, and n is index of refraction of air. From the formulait is evident that the thicker the plastic, the lower the pitch orlenticules per inch (LPI), and the lower the pitch, the coarser thelens. A coarse lens can give undesirable lens effects, for example,distortion of an underlying image. A coarser lens requires imagegraphics and text to be significantly large to avoid undesirable lenseffects. When printing a lenticular image on a lenticular lens, the lensneeds to be parallel to the interlaced image, such as, for examplewithin +/−½ lenticule per ten inches. If this is not maintained, theimage does not have an acceptable vertical flip, but rather a skewedflip. Skew can be defined as unacceptable ink-to-lens registrationaccuracy of the printed vertical lenticular image elements to thevertical lenticular lenses.

Another type of dimensional imaging technology includes fly's eye orbug's eye image technology. Fly's eye or “integral” lens arrays areformed from a web or sheet including a plurality of domes orsemi-circular structures extending from the surface, rather than theelongated lenses of lenticular technology. Similar to lenticular, animage, such as an interlaced image, can be printed on the planar side ofthe lens sheet or web, or printed on a separate substrate and laminatedthereto. There are a number of benefits to using a fly's eye lens asopposed to a lenticular lens. The fly's eye lens is essentially alenticular lens in multiple directions tangentially around the lens.This essentially allows one not only to interlace an image from left toright (horizontal direction), but also up and down (vertical direction),diagonally, or in any combination to give additional animated effects.

Current methods of producing dimensional images, such as lenticularimages, include printing of lenticular sheets through a sheet-fed orweb-fed press where, as discussed above, the caliper ranges from about10 mils to about 40 mils. Alternatively, the caliper of the lens sheetsor webs can be from 10 mils or less, thereby forming thin film displaydevices. Examples of thin film technologies are described in U.S. Pat.No. 6,424,467 to Goggins, U.S. Pat. No. 7,359,120 to Raymond et al., andU.S. Patent Application Publication No. 2010/0134895, entitled “ThinFilm High Definition Dimensional Image Display Device and Methods ofMaking Same,” all of which are incorporated herein by reference in theirentireties. Novel imaging or printing techniques, known commercially asInfinidepth®, do not require the critical ink-to-ink registration oftraditional interlacing and therefore can be used on thinner lenses withhigher lens densities, as described in one or more of U.S. PatentApplication Publication Nos. U.S. Application Publication Nos.2008/0088126 entitled “Layered Image Display Applications and Methods,”2008/0088931 entitled “Layered Image Display Sheet,” and 2008/0213528entitled “Customized Printing with Depth Effect” all of which areincorporated herein by reference in their entireties.

Whether in thin film format or thicker rigid format, it can be desirableto impart visual effects such as three dimensionality or motioncharacteristics on only select areas of a surface or article, as opposedto an entire surface, typically referred to as “spot” lenticular. Onesuch method of spot lenticular is described in U.S. Pat. No. 7,002,748to Conley et al. Another technique includes a varied lenticular lensarray, in which the density and/or shape of the lenticules are alteredon a single surface is described in U.S. Pat. No. 7,609,450 to Niemuth.

However, in each of these examples, the lenses extend above the base orplanar surface making it difficult to print either a first surfacearound the lenticular features, or the second opposite planar surfaceafter the array has been formed because the varying caliper and unevensurface makes it difficult or impossible to maintain constant pressurethrough a contact-based printing press, such as in offset printing,resulting in poor print quality and/or distorted lenses. For example,when a web or sheet of varying caliper is printed via an offsetflexographic or lithographic printing process, the variance in caliperbetween the planar and lenticulated areas causes uneven pressure in thenip formed by the impression cylinder and the blanket or offsetcylinder, thereby resulting in variations in color densities. A varianceas little as two or more mil can result in poor quality printing. If thepressure is increased to maintain even pressure over the sheet, thelenses or lenticules are forced at high pressure either into the blanketcylinder or the impression cylinder, depending on what surface is beingprinted, which can result in distortion of the lenses and permanentdamage to the blanket.

Further, if a lens sheet having a lens array in which the lenses extendabove the planar surface is married or bonded to a substrate, such as aprinted substrate, the uneven caliper or surface can cause difficulty ina nipping process (nip pressure or bonding pressure) used to mount thesheets together. Similar to the problems associated with contact-basedprinting, the lenses or lenticules are forced at high pressure into niprollers, which can result in distortion of the individual lenses orcaliper variation or bubbling.

When printing a number of sheets, it is common to use equipment thatautomatically feeds each sheet into the printing press from a stack. Inboth contact and contactless printing such as inkjet and other digitalprinting techniques, a variance in caliper of the sheet can result inpoor or inconsistent autofeeding capabilities because the equipment maymisjudge the location of the next sheet from the stack, either grabbingno sheet or more than one sheet due to pile curl or waviness. Similar tosheet-fed processes, caliper variance in web rolls (sometimes calledgauge banding) can cause inconsistent web gauging which in turn cancause problems with unwind and/or rewind processes, as well ascalibration of one or more systems in the webline, such as the unevenprinting pressure described above. Furthermore, caliper variance cancause similar issues, whether in sheet or web form, in cuttingprocesses, and/or stacking off-press. For example, in a contact-basedcutting process, such as a guillotine or die-cutting process, calipervariance can cause misjudgment of the depth of cut needed, resulting intoo shallow of a cut such that the web or sheet is not completely cutthrough, or the cut is too deep which can cause damage to the die, oreven result in the die rule being buried in a cutting surface. Inaddition, caliper variations in the diecutter could cause infeed andstripping operation problems.

Therefore, there remains a need for a lens sheet having one or more lensarrays in select areas that can be economically and efficiently producedand printed for use with any of a variety of articles for offeringspecial visual effects such as three-dimensionality, magnification,and/or animation, and that can be delivered in a flat format, such as aflat stack or roll.

SUMMARY OF THE INVENTION

According to embodiments of the invention, a lens sheet having lensarray in one or more preselected areas generally includes a substratehaving a first surface and a second generally planar surface. Forclarity purposes, “lens sheet” can refer to either a sheet or webformat. Furthermore, “lens sheet” can refer to a single piece, or asheet containing multiple pieces to be converted or produced therefrom.The first surface includes one or more generally planar portions, andone or more lens array areas, wherein the peaks of the lenses in each ofthe lens array areas are in the same plane or below the plane formed bythe generally planar portions to thereby decrease the overall thicknessof the lens sheet, and to provide a sheet having generally uniformcaliper, i.e. one that is in a flat format such that it can be stackedin a flat stack or roll, and presents generally flat surfaces to aprinting process with no lenses extending above the planar surface suchthat even pressure can be maintained during printing.

The lens sheet can be formed of a transparent or translucent material,and optionally include a printed image layer on the second generallyplanar surface or second substrate (e.g. backing sheet) that optionallyis at least partly “viewable” such that the image layer is recognizable,human- or machine-readable, decoded, and/or legible, through the one ormore lens array areas, resulting in a visual effect includingthree-dimensionality, motion or animation, depth effects, magnification,and/or combinations thereof. Additional static or flat printed imagescan be formed on the second surface or second substrate and are viewablethrough the one or more generally planar portions of the first surface.Additionally or alternatively, one or more static or flat printed imagescan be formed on the one or more generally planar portions of the firstsurface.

Methods of making a lens sheet having one or more lens arrays inpreselected areas include forming one or more lens arrays in an area ofthe first surface of a polymeric sheet or material by extrusion,embossing, injection molding, or any of a variety of patterningtechniques. In one embodiment, a plastic material is extruded orsupplied to a patterned cylinder or plate having a relief of the desiredlens array pattern(s), such that the lens array(s) are formed in theplastic material. The remaining portions of the first surface includeone or more planar portions. Each lens array comprises a plurality oflenses, and the peaks of the lenses do not extend above the one or moreplanar portions. Optionally, one or more of the lens array(s) isentirely bordered by at least one planar portion.

The lens sheet can be used in a variety of applications including thinfilm or thicker, rigid film applications. Some applications can include,but are not limited to, thin film packaging, the card industry includingidentification, transaction, gift, greeting, and game cards, currency,security features, packaging such as box packaging, advertising andmarketing such as promotional items, posters, and the like, or any of avariety of contemplated uses in which special visual effects aredesired.

The above summary of the invention is not intended to describe eachillustrated embodiment or every implementation of the present invention.The figures and the detailed description that follow more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a portion of a lenticular arrayaccording to the prior art.

FIG. 2 is a cross-sectional view of an engraved lenticular patternaccording to the prior art.

FIG. 3A is a cross-sectional view of a portion of a lens sheet with alens array according to an embodiment of the present invention.

FIG. 3B is a top view of the lens sheet of FIG. 3A illustrating onevariety of fly's eye lenses.

FIG. 4 is a front view of a piece with two lens arrays per piece, onearray having lenses running perpendicular to the lenses of the otherarray, according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of a portion a printed lens sheet witha lens array according to an embodiment of the present invention.

FIG. 6 is a front view of a piece with a lens array and matte finishaccording to an embodiment of the invention.

FIG. 7 is front view of a piece with a lens array, a gloss area, and amatte finish according to an embodiment of the invention.

FIG. 8 is a front view of a piece with a lens array, and a texturedfinish according to an embodiment of the invention.

FIG. 9 is a front view of a piece with an integral square fly's eye lensarray according to an embodiment of the invention.

FIG. 10 is a front view of a piece with three different lens arraysthereon, including an integral fly's eye array and two lenticular arraysrunning perpendicular to one another, according to an embodiment of theinvention.

FIG. 11 is a cross-sectional view of a composite piece including twolens sheets according to an embodiment of the invention.

FIG. 12 is an exploded cross-sectional view of a portion an engravedlens pattern according to an embodiment of the present invention.

FIG. 13 is a flow diagram for patterning a cylinder used to produce lenssheets according to an embodiment of the present invention.

FIG. 14 is a front view of a lens sheet including multiple lens arraysprepared by the method of FIG. 13.

FIG. 15 is a perspective view of a cylinder used to produce a lens sheetaccording to the method of FIG. 13.

FIG. 16 is a schematic of a lens sheet with multiple pieces, and anindividual piece with points of measurement according to an embodimentof the present invention.

FIG. 17A is a graph of caliper measurements of Sheet A of the Example atlocations A-D.

FIG. 17B is a graph of caliper measurements of Sheet A of the Example atlocations E-F.

FIG. 18A is a graph of caliper measurements of Sheet B of the Example atlocations A-D.

FIG. 18B is a graph of caliper measurements of Sheet B of the Examplesat locations E-F.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, a spot lenticular lens sheet 10 according to theprior art includes a transparent sheet 12 having a first surface 14 anda second surface 15 separated by a sheet thickness 17. First surface 14includes a lens array 16 and planar portions 18. Lens array 16 is madeup of a plurality of lenticular lenses 20, i.e. elongated convex lightsteering devices. Each lens 20 has a width 22, and a lens height 24measured from first surface 14 to a peak 26. As shown, lenses 20 extendabove or beyond a plane formed by first surface 14. Therefore, anoverall thickness 28 of lens sheet 10 includes sheet thickness 17 andlens height 24.

Referring to FIG. 2, the prior art lenticular lens sheet 10 can beformed by extrusion, embossing, or casting using an engraved cylinder orplate 50, having a lens pattern 52 defined thereon. Lens pattern 52 isthe sunken relief of lens array 16 of FIG. 1. As depicted, lens pattern52 is sunken from the plane of the cylinder or plate, thereby formingraised lenses on first surface 14.

Referring to FIG. 3 a, a spot lens sheet 100 according to embodiments ofthe present invention generally includes a sheet 102 having a firstsurface 104 and a second surface 106 separated by a sheet thickness 108.Sheet 102 can be formed from one or more plastic materials such as, forexample, polyester, polycarbonate (PC), polyvinyl chloride (PVC),polyethylene terephthalate (PET), amorphous polyethylene terephthalate(APET), glycol-modified polyethylene terephthalate (PETG), polypropylene(PP), polyethylene (PE), polystyrene (PS), and other suitable plasticsand combinations thereof. The plastic material can be transparent ortranslucent such that a dimensional image or other indicia or printedmatter can be seen therethrough. Alternatively, when it is not desiredto view a dimensional image therethrough, the plastic material can beopaque.

First surface 104 includes one or more areas defining a lens array 110,and one or more planar portions 112. Each lens array 110 comprises aplurality of light steering optical lenses 114, such as, for example, alenticular, integral web (fly's eye), or any of a variety of suitablelens shapes such as round, oval, square, rectangular, triangular, or thelike, and/or combinations thereof. In one embodiment of the invention,the lens array comprises an integral web or fly's eye array such thatthe animation can be incorporated in the horizontal, vertical, ordiagonal direction, or any combination thereof. Lens array 110 can becompletely within the borders of lens sheet 100, surrounded by planar ornon-lens portions, such as illustrated in FIGS. 3 and 4, can make up oneor more borders of the sheet (not shown), or can be a combination ofboth (not shown).

As illustrated in FIG. 3A, each lens 114 has a lens width 116 and a lensheight 118. Lens array 110 lies at or below planar portion 112 such thata peak 120 of a lens 114 (or alternatively the peak 120 of each lens114) lies flush with or below the plane formed by first surface 104,such that lens height 118 is equal to or less than sheet thickness 108.Therefore, the overall thickness or caliper of lens sheet 100 is equalto the sheet thickness 108. Sheet thickness 108 can range from about onemil to about 50 mils, or greater, such as from about 50 mils to about100 mils or more. For traditional purposes, such as game cards ortransaction cards, sheet thickness 108 can range from about 10 mils toabout 50 mils. For thin film purposes, such as packaging, sheetthickness 108 can be 10 mils or less.

In one embodiment of the invention, a lens sheet comprises multipleselect areas defining a lens array, each of the lens arrays being setbelow or flush with the planar areas of the first surface, andoptionally, but not limited, completely contained within or bordered bynon-lens or planar portions such that the arrays are discrete areas ofthe sheet. Multiple individual pieces can be converted from the lenssheet.

A first lens array comprises a plurality of lenses at a first lens pitch(lenses per inch), each of the lenses having a first lens height that isequal to or less than the sheet thickness, and a second lens arraycomprises a plurality of lenses at a second lens pitch, each of thelenses having a second lens height that is equal to or less than thesheet thickness. The first lens height of the lenses of the first arraycan be either substantially equal to or different from the second lensheight of the lenses of the second array. Further, the first lens pitchcan be the same as or different from the second lens pitch. Additionallyor alternatively, a first optical focus or focal length of the firstlens array is the same or different than a second optical focus or focallength of the second lens array. The optical focus or focal length isthe distance at which a beam of collimated light will be focused to asingle spot behind the lens when viewed through the front of the lensarray.

In another embodiment of the invention, and referring to FIG. 4, a piece400, such as a card, from a lens sheet comprises multiple lens arrays402, including a first lens array 402 a and a second lens array 402 b.In this particular embodiment, each lens arrays 402 a, 402 b comprises aplurality of lenticular lenses 404. Lenses 404 a of first lens array 402a are orientated in a first direction, e.g. parallel to a vertical sideedge 406 a of piece 400. A dimensional effect, i.e. motion or “flip”,produced by lens array 402 a coupled with an image, such as a firstinterlaced or Infinidepth® image, is observed when piece 400 is shiftedor a viewing angle is shifted left-to-right and vice versa. Lenses 404 bof second lens array 402 b are orientated in a second directiondifferent than the first direction, e.g. parallel to a horizontal sideedge 406 b of piece 400. A dimensional effect, i.e. motion or “flip”,produced by lens array 402 b coupled with an image, such as a secondinterlaced image or Infinidepth® image, is observed when piece 400 isshifted or a viewing angle is shifted top-to-bottom (or up/down) andvice versa. The first and second directions are not limited to beingparallel to the side edges of piece 400, and any combination oforientations can be contemplated. In general, dimensional effect, i.e.motion or “flip”, of a particular lens array is observed when piece 400is in a direction substantially perpendicular to the orientation of thatlens array.

In another embodiment of the invention, a first lens array has a firstoptical focus, and a second lens array has a second optical focusdifferent than the first optical focus. The first optical focus issufficient for viewing a dimensional image placed proximate the lensarray, such as printed on the opposite surface of the sheet from thelens array. The second optical focus is greater than the first opticalfocus such that it is held at a distance from a dimensional image forviewing the image therethrough, such as in the case of a decoder/hiddenmessage system.

Referring to FIG. 5, a display sheet 126 comprises lens sheet 100 havingone or more lens array 110 and planar portions 112 on first surface 104.A dimensional printed image 128 is applied under each lens array 110 onsecond surface 106 such that printed image 128 is viewable through lensarray 110, thereby creating a visual effect, such as threedimensionality, magnification, and/or animation, to a viewer.

Optionally, planar portions 112 of first surface 104 and/or secondsurface 106 can be printed or otherwise treated with one or more staticimages or layers 130, in addition to printed image 128 or as analternative to printed image 128. In one embodiment, lens sheet 100 issufficiently transparent or translucent such that any image(s) 130printed on second surface 106 is viewable through planar portion(s) 112of first surface 104. Images 130 can comprise such as text, variabledata, graphics, patterns, logos, and/or ink layers such as colors,opaque ink such as flood or spot white, metallic, foil or anycombination thereof, thereby adding to the visual aesthetic of thearticle having the display sheet thereon. In one particular embodiment,first surface 104 and/or second surface 106 are cold foiled, hot foiled,hot stamped, laminated, ebeam foiled, or otherwise spot foiled, such asdescribed in U.S. Application Publication No. 2010/0086753 entitled“Foiled Articles and Methods of Making Same,” incorporated herein byreference in its entirety. In another embodiment of the invention,multiple customized pieces can be fabricated from the lens sheet inwhich each piece contains variable data, such as described in U.S.Provisional Application No. 61/382,213 entitled “Mass Customization ofArticles Having Dimensional and/or Animated Images,” incorporated hereinby reference in its entirety.

Printed image 128 and/or static image(s) 130 can be printed or otherwiseapplied directly onto second surface 106. Additionally or alternatively,printed image 128 and/or static image(s) 130 are applied to a secondsheet (such as, for example, but not limited to, a backing sheet). Thesecond sheet containing printed image 128 and/or static image(s) 130 isthen correlated or registered with lens sheet 100 such that printedimage 128 on the second sheet is viewable through lens array 110 ondisplay sheet 126, and/or static image(s) 130 is viewable through planarportions 112 of display lens 100. In this situation, lens sheet 100,printed image 128, and second sheet make up a composite lens sheet ordisplay sheet.

Optionally, one or more opaque ink layers can be applied over theprinted image 128 and optional static image(s) 130 applied to secondsurface 106 such that additional printing or markings can be applied tosecond surface 106 that are not viewable through lens sheet 100, whetherthrough lens array 110 or planar portions 112 of first surface 104. Inan alternative embodiment, an opaque backing sheet, such as a plastic orpaper backing sheet or a laminate can be applied to second surface 106over any printing thereon. The backing sheet can be applied by any knownmeans in the art, such as, for example, adhesives or other bondingtechniques.

Additional layers can be applied either directly to the second surfaceor the backing sheet (if present). These additional layers can comprise,for example, text, variable data, graphics, logos, personalidentification numbers (PIN), account numbers, machine-readable indiciasuch as magnetic stripes, barcodes, RFID, QR codes, and the like, or anycombination thereof. In one particular embodiment, indicia such as abarcode or magnetic stripe is printed on the second surface or thebacking sheet (if present) on a side opposite the lens sheet. A laminateor other protective coating is then applied over the indicia, such asdescribed in U.S. Provisional Application No. 61/480,213, entitled“Articles Having Machine or Human Readable Indicia Imaged Under a TamperProof Layer for Theft Prevention,” incorporated herein by reference inits entirety. Alternatively, the indicia can be applied to the secondsurface or backing sheet (if present) such that it is “readable” oridentifiable through the first surface and/or lens array. In yet anotheralternative embodiment, the indicia is applied to the planar portion ofthe first surface and a protective laminate or other coating is appliedover the indicia.

Images 128 and 130 can be printed using any of a variety of suitableprinting techniques, such as, for example, flexographic, lithographic,gravure, rotogravure, digital inkjet, digital toner, screen printing,and the like or combinations thereof. Images 128 and 130 can be printedusing traditional and non-traditional inkjet ink, dry offset ink, lithoink, flexo ink, silk screen ink, latex ink and the like in one of theaforementioned printing techniques or combination of techniques. Theinkjet ink used may be a traditional solvent- or UV-based ink. In oneembodiment, UV curable inks can be used, such as SUNCURE inkscommercially available from Sun Chemical of Carlstadt, N.J., and UVcurable inks commercially available from Flint Inks of St. Paul, Minn.Other suitable printing materials or media can include toners, water- orsolvent-based inks, solventless inks, other forms of radiation curableinks, or combinations thereof. The printing media is optionally curedwith one or more appropriate curing system as needed.

Referring to FIG. 5, dimensional image 128 is printed directly onto lenssheet 100, and/or onto another substrate that is laminated to lens sheet100. In one embodiment of the invention, dimensional image 128 isprinted using an image technique that does not require precisecolor-to-color or ink-to-ink registration accuracy. For example, oneimage technique is one-color animation where the animation image isincorporated in a single color of the process colors, such as a 4-CPimage. In other embodiments of the invention, the image technique ismulti-color animation where the several colors are located in the samearea of a substrate but animation is independent with respect to eachcolor. In another embodiment of the invention, the image technique is aform of hologravure, otherwise known as Infinidepth®, which includes aholographic fringe pattern that gives a depth or 3D effect, againincorporated in a single color of the process colors, such as a 4-CPseparation or image. In yet another embodiment of the invention, theimage technique is bi-directional interlaced imaging in which two ormore images are interlaced in two directions, such as horizontally andvertically. In yet another embodiment of the invention, a combination ofone or more of these image techniques is incorporated.

In one embodiment of the invention, multiple interlaced images areprinted that correspond to multiple lens arrays, each lens array havingits own orientation, pitch, shape, and dimensions the same or differentfrom the other lens array(s). In particular, and referring back to FIG.4, a first interlaced image can comprise two or more images interlacedand printed or otherwise mounted in a first orientation for viewingthrough first lens array 402 a. A second interlaced image can comprisetwo or more images interlaced and printed or otherwise mounted in asecond orientation for viewing through second lens array 402 b.

In an alternative embodiment not shown, a lens sheet comprises a fullyflooded lens sheet in which the first surface is entirely made up oflenses, including multidirectional lens arrays. For example, a firstlens array comprises lenses oriented in a first direction, and a secondlens array comprises lenses oriented in a second direction differentfrom the first direction. For example, a picture frame is formed from amultidirectional lens sheet. An outer border comprises lenses orientedin a first direction, such as a substantially horizontal direction,while an inner portion comprises lenses oriented in a second directiondifferent than the first direction, such as a substantially verticaldirection.

In an alternative embodiment of the invention not shown, lens sheet doesnot include a dimensional printed image such that each lens array is itsown feature. In one particular example, each lens of a lens array areindividually formed into a recognizable or trademarked shape, and/or thearray as a whole, i.e. the perimeter shape of the array, is formed intoa recognizable or trademarked shape. In yet another embodiment of theinvention, a lens sheet includes a first lens array having nodimensional printed image bonded thereto, and a second lens array havinga dimensional printed image bonded thereto, as described above. Theendless combinations of printing, number of lens arrays, lens shapes,dimensions, and lens array orientations is selected based upon thedesired level of stimulation of the consumer.

A variety of lens sheet combinations are herein described. At least oneof the lens arrays of each embodiment includes a plurality of lensesflush with or below the lens-free area as previously described.

Referring to FIG. 6, a lens sheet can comprise one or more pieces 600,such as cards, that are ultimately cut out of the lens sheet. Piece 600comprises at least one lens-free area 602 and at least one lens array604 flush with or below lens-free area 602. In this particularembodiment, lens-free area 602 comprises a matte finish.

Referring to FIG. 7, piece 700 comprises at least one matte lens-freearea 702, at least one lens array 704 flush with or below lens-free area702 and at least one discrete gloss lens-free area 706. In this example,gloss area 706 is registered with respect to the length and width ofpiece 700 such that it is fully nested within the perimeter of piece700. However, it can also be contemplated that gloss area 704 comprisesat least part of one or more edges of piece 700. Alternatively (notshown), a matte area can be registered in a select position, and theremaining lens-free portions comprise gloss areas.

Referring to FIG. 8, piece 800 comprises at least one lens-free area 802and at least one lens array 804 flush with or below lens-free area 802.At least a portion of lens-free area 802 comprises a texture, such as awood grain, bump or football texture, polka-dotted, or any of anunlimited variety of textures, such that it is unsmooth.

Referring to FIG. 9, piece 900 comprises at least one lens-free area 902and at least one lens array 904 flush with or below lens-free area 902.Lens array 904 comprises a “spot square” array, i.e. an integral orsquare fly's eye pattern, although any other shape can be contemplatedas described supra. Lens-free area 902 can comprise a matte finish,gloss finish, textured finish, or any combination thereof, as describedabove.

Referring to FIG. 10, piece 1000 comprises at least one lens-free area1002, a first lens array 1004 a, and at least another lens array 1004 bdifferent in at least one of pitch, shape, size, type, orientation, thanfirst lens array 1004 b. In this particular example, first lens array1004 a comprises a “spot square” array, i.e. a square fly's eye patternoriented in a first direction, and second lens array 1004 b comprises alenticular lens array orientated in a second direction, either the sameor different than the first direction. Piece 1000 can further comprise athird lens array 1004 c, such as a lenticular lens array, oriented in athird direction different than the second direction. Lens-free area 1002can comprise a matte finish, gloss finish, textured finish, or anycombination thereof, as described above.

Referring to FIG. 11, piece 1100 comprises a composite piece having afirst lens sheet 1102 coupled to a second lens sheet 1104. At least lenssheets 1102 comprises at least one lens array 1106 flush with or below alens-free area 1108. Lens sheet 1104 can comprise at least one lensarray 1110 flush with, below, or raised above a lens-free area 1112. Atleast one ink layer 1114 a, 1114 b is optionally printed or otherwiseplace behind lens sheets 1102, 1104. An optional opaque or translucentadhesive layer and/or laminate layer 1116 can be sandwiched between thetwo lens sheets.

As illustrated in FIG. 12, spot lens sheets can be formed by extrusion,embossing, or casting using an engraved, or otherwise formed, cylinderor plate 122, having an inverse lens pattern 124 defined thereon. Lenspattern 124 is the inverse or relief of lens array 110 of FIGS. 3A and3B. As depicted, lens pattern 124 is raised from the surface of thecylinder or plate, thereby forming lenses on first surface 104 in whichthe peak of the lenses lie at or below the planes form by first surface104.

To make a lens sheet or piece with multiple lens arrays in multipledirections, such as piece 400 or sheet of such pieces, a flat plate isengraved as described above with bidirectional or multidirectionalpatterns, and a clear lens material is pressed or embossed with thepattern either before or after printing. Alternatively, a cylinder isengraved with bidirectional or multidirectional patterns to form a clearlens sheet via extrusion. Alternatively, a stamper can be engraved witha spot lens, bi-directional or multidirectional pattern, and the lenssheet is created by injection molding.

Lens pattern(s) 124 can be formed directly onto a cylinder surface or aplate surface by any of a variety of processes with sufficient precisionincluding, but not limited to, mechanical machining such as diamondturning or single point diamond turning, laser engraving, etching, orcombinations thereof. In an alternative embodiment of the invention,lens pattern 124 is formed in a flat, thin plate, and subsequentlycoupled to a cylinder by adhesive, magnetism, or other attachmentmechanisms. In this case, lens pattern 124 is formed in the plate toaccount for its use on a curved cylinder. Alternatively, lens pattern124 can be cut or engraved into a cylinder, and thereafter formed into aplate by unwrapping or peeling away a layer of the cylinder. The platecan also be used as a stamper in injection molding processes.

In one particular embodiment of the invention, and referring to theprocess flow diagram of FIG. 13, a method 1300 for engraving orpatterning a cylinder for producing lens sheets according to embodimentsof the invention is illustrated. At 1302, a desired lens sheet size isdetermined based on constraints of the subsequent extrusion or embossingprocess and/or the printing process. For example, a lens sheet can havea maximum length (i.e. direction of travel through the printing press),due to printing press constraints, of 28.375″. It can be generallyadvantageous to run a sheet that is no wider than it is long. Therefore,a desired sheet size in the example is a square sheet having dimensionsof 28.375″×28.375″. Based on the value of the cylinder diameter of aparticular extrusion process, the cylinder circumference is thencalculated using the formula: cylinder circumference=n*cylinderdiameter. For example, a maximum cylinder diameter of a particularextrusion process can be 18.0732″ which gives a maximum cylindercircumference of 56.75.″ The maximum number of lens sheets perrevolution of the cylinder is then determined. For example, a cylindercircumference of 56.75″ allows two sheets having a length of 28.375″(and width of 28.375″) to be produced in a single revolution. The methodis not limited to the example; rather, depending on the cylinder and/orprinting press capabilities, one can adjust the sheet size and/orcylinder dimensions accordingly. For example, if the cylinder diameteris a constraint, the sheet size can be adjusted to fit the cylinderaccordingly. Additional or alternatively, if the subsequent printingprocess is a constraint, such as a sheet width and/or length maximum,the cylinder dimensions can be adjusted accordingly. Method 1300 is ahybrid of both lens sheet dimension limitations based on printing presscapabilities, and cylinder dimension limitations based on extrusion,casting, or embossing capabilities, such that the optimum sheet size isdetermined within the bounds of the printing press and cylinderconstraints.

At 1304, the desired sheet design is determined, i.e. the position ofthe one or more lens arrays on each lens sheet is determined. Forexample, if multiple pieces are formed from one lens sheet, one or morearrays or pattern of arrays can be repeated over the length and/or widthof the sheet. It is important that the position of each lens array (bothacross the width and along the length of the sheet) is tightlycontrolled so that it is substantially the same from sheet to sheetwithin a tolerance. This tight registration is to ensure that thesubsequent printing of the lens sheet is highly registered. In oneparticular embodiment, illustrated in FIG. 14 using a lens sheet 1400having multiple lens arrays 1402, a tolerance is 1/32″ in each of the xand y positions from sheet to sheet, the x position being along thelength of the sheet at a distance “x” from a side edge 1404 a, and the yposition being across the width of the sheet at a distance “y” from aside edge 1404 b.

Referring back to FIG. 13, at 1306, flat areas corresponding to theplanar portions of the lens sheet are etched from the surface of thecylinder, thereby leaving discrete raised areas or “islands”corresponding to the lens arrays, their locations being determined bythe desired sheet design. The sheet design is repeated along thecircumference of the cylinder based on the number of sheets perrevolution to be produced. In one embodiment of the invention, the flatareas are formed by photo-etching. A photo-mask of the desired lenssheet pattern is formed from a negative photo resist material over thecylinder. The photo resist material is exposed, therefore forminginsoluble areas in areas of the cylinder corresponding to the lens arrayareas on the lens sheet(s). The unexposed or unprotected areas areetched away using an acid bath. The etched areas define the “flat” orplanar areas of the lens sheet. The photo-resist is then removed fromthe resulting raised areas. Alternatively, laser etching can be used toetch the planar areas. Alternatively, a laser etching process can beused.

At 1308, the raised areas are engraved, such as by laser engraving ordiamond tool engraving, to form the inverse lens pattern 124 (of FIG.12) of each lens array of the sheet(s).

At 1310, optional processing steps are also contemplated. For example,one or more flat areas can be polished to form a resulting gloss,semi-gloss, or matte pattern on the resulting sheet. Alternatively, atexture or other pattern can be introduced into the cylinder. Suchtextures can include, for example, a wood grain, a “bump” pattern suchas a football pattern or a polka-dotted pattern, cross-hatching, or anyof an unlimited variety of patterns. For example, to produce a lenssheet with one or more gloss planar portions, the flat areas of thecylinder are polished to a finish referred to as an “A2” finishaccording to SPI Standards (the plastics industry trade association). An“A-2” finish is an A-2 Grade #6 Diamond Buff which is similar to an A-1diamond finish but with less shine. To produce a lens sheet with one ormore matte planar portions, the flat areas of the cylinder are polishedto a finish of a D-finish, which is a dry blast finish, which can varydue to the material blasted, the amount of pressure used, and thedistance the blast is applied. A table of different finishes per the SPIStandards is included below. Alternatively, a matte finish can beaccomplished by applying a light texture, such as an MT 11010 finetexture, known to one of ordinary skill in the art as a subtle andshallow texture of fine grained character.

TABLE 1 Finish per SPI Standards Grade Description A-1 Grade #3 DiamondThe finest diamond finish mostly used for Buff finishing clear lenses,optics and critical cosmetic parts A-2 Grade #6 Diamond Close to an A-1diamond but with less shine Buff than A-1 diamond. Typically used onmolds that produce cosmetic parts. A-3 Grade #12 Diamond Close to an A-2diamond but with less shine Buff than A-2 diamond. Typically used onmolds that produce cosmetic parts that don't require a high finish. B-1600 Grit Paper The highest finish before diamond process. Mostly used onhighly cosmetic parts that are chrome plated or painted (Close to A-3diamond with a directional pattern). B-2 400 Grit Paper Close to a B-1paper finish, but with a deeper directional pattern. Less shine than a600- paper finish. B-3 320 Grit Paper Almost like a B-2 paper finish,but with a slightly deeper directional pattern. B-4 240 Grit PaperDeeper directional pattern than 320 paper finish typically used afterstone for ease of finishing and appearance. B-5 P180 Grit Paper Deeperdirectional pattern than 240 paper finish typically used after stone forease of finishing and appearance. C-1 600 Stone Finish Fine smoothfinish mainly used on small detailed areas where paper finish is notfeasible. C-2 400 Stone Finish Slightly rougher finish than 600 stone.Mainly used for removal of fine machined finishes, where rougher stonesmay not necessary to use. C-3 320 Stone Finish General purpose startingand finishing stone to remove machine finished. C-4 220 Stone FinishGeneral purpose starting stone to remove rougher machined finishes.Deeper finish than 320-400 stone may be used for final finishing. C-5150 Stone Finish Mostly used to remove very rough machined finishes.Note: Paper grit finishes are not equivalent to their stonecounterparts. (Example: A320 paper finish = approx. a 600 stone finish,320 paper is twice as fine as 320 stone.) Note re D-finishes: Dry blastfinishes may vary due to material blasted; the amount of pressure usedand at what distance blast is applied. Blast material will break downand can't be used indefinitely to achieve same results at givenspecification.

In one particular embodiment of the invention, optional registrationmarks are etched or engraved into the cylinder during the etchingprocess in 1306, and/or in the optional processing step 1310. Theregistration marks can indicate, for example, the position indicatingthe end of one sheet and beginning of another sheet. A detector in acutting system of the extrusion process reads or detects theregistration mark embossed in the plastic lens sheet during theextrusion process from the cylinder, which in turn triggers a cuttingdevice to cut in an exact location, resulting in a highly registered cutsheet. Additionally or alternatively, registration marks can be etchedinto the cylinder to therefore form physical marks in the resultingsheet for the purposes of printing registration. A device on asubsequent printing process reads or detects the registration mark,triggering the printing head of a print engine to print at a specificlocation on the sheet. For example, referring back to FIG. 14, lenssheet 1400 includes a registration mark 1406 either in the form of aprinted or physical mark in the surface of the sheet.

Referring to FIG. 15, a cylinder 1500 formed from method 1300 isillustrated. Cylinder 1500 includes flat areas 1502, and raised engravedareas 1504 comprising the inverse of one or more lens patterns. In thisembodiment, raised engraved areas 1504 comprise discrete “islands”within flat areas 1502. In an alternative embodiment (not shown), one ormore raised areas can extend the entirety of the circumference of thecylinder, or the width of the cylinder depending the desired lenspattern. Further, cylinder 1500 includes registration marks 1506.Cylinder 1500 allows a lens sheet to be manufactured with registered“spot” patterns of lens arrays, such as shown in FIG. 14. The spotpatterns are registered within tight tolerances, such as 1/32″ or less,both across the sheet and along the length of the sheet, as shown inFIG. 14.

Subsequent to preparing the patterned cylinder or plate, the patternedcylinder or plate is placed into a lens sheet process of manufacture.Inverse lens pattern 124 as shown in FIG. 12 of each lens array is thentransferred to a sheet material using known conventional extrusionand/or embossing methods, thereby forming lens array 110 (FIGS. 3A, 3B)on the sheet in the desired select areas only. If registration marks arepresent, the sheets are automatically cut at a preselected location upondetection of the registration mark by the appropriate sensing device.Additionally or alternatively, the extrusion line or embossing line cancomprise slitting wheels positioned on one or both edges of the sheet totrim excess side edge material from the sheet so that the sheet istrimmed to the desired length and width.

Printed display sheets, such as display sheet 126 of FIG. 4, can befabricated using a number of low cost, high speed processes, many ofwhich are described in detail in U.S. Patent Application Publication No.2010/0134895, which was previously incorporated by reference in itsentirety. In one embodiment of the invention, a high speed printingprocess, such as a digital printing system, using a pre-fabricated lensweb or sheet having one or more lens arrays 110 in select locationsacross and down web is used. The lens array film web or sheet is formedby embossing, casting, casting and curing, extrusion, or the like, asdescribed above.

In another embodiment, a web press is used incorporating inline printingand embossing such that a transparent film is printed on the firstand/or second surfaces of the film before and/or after a lens array isembossed on the first surface of the film in select locations.Alternatively, discreet sheets are printed on the first and/or secondsurface before and/or after a lens array is embossed on the firstsurface of the film in select locations.

In yet another embodiment of the invention, a web press is usedincorporating inline printing and extrusion, such that a transparentfilm is extruded onto a patterned cylinder to form the lens array inselect locations, and printed on the first and/or second surfaces of thefilm. Alternatively, discreet sheets are extruded and then printed onthe first and/or second surface. In yet another embodiment of theinvention, a web press is used incorporating inline printing andcasting, such that a coating is cast onto a film and subsequentlypatterned and optionally cured to form the lens array in selectlocations, and printed on the first and/or second surfaces of the filmbefore and/or after forming the lens array. Alternatively, discreetsheets are formed.

The display devices including the lens sheet and printed image or lenssheet alone, according to embodiments of the invention, can be used in awide variety of applications and articles. It can be subsequentlyconverted or manufactured into packaging films, labels, stickers, orwrappers that later can be applied to or around a formed product orformed products. Alternatively, the device can be used alone, orlaminated to one or more other substrates to form the article itself,such as a wrapper, bottle, poster, flexible packaging, or the like. Inyet another embodiment, the dimensional image display device comprises arigid article, such as, for example, a gift card, transaction, debit, orcredit card, a loyalty card, a trading card, a game piece, anidentification card, a key card, a postcard, or any of a variety ofrigid cards or pieces. In another embodiment, the dimensional imagedisplay device can be used in security applications such as, forexample, security labels, tax stamps, identification cards anddocuments, checks, currency, authentication labels, and the like. Forexample, an authentication label incorporating a dimensional imagedisplay device for high end often copied products can be useful for easeof identification by a customs agent to identify a copied product.

In one embodiment of the invention, the display device is incorporatedon a curved surface, such as the surface of a cup or other container.The display devices can form the cups themselves, such as a single usecup, or can be used as inserts or sleeves in injection molded cups, orcan be used as labels for application to a curved surface. The printeddimensional image is printed to accommodate for the curved surface, suchas printing along an arc corresponding with a sweep angle of the curvedsurface. Such printing is described in, for example, U.S. ApplicationPublication No. 2008/0088931 entitled “Layered Image Display Sheet,”previously incorporated by reference in its entirety, and U.S. Pat. No.6,490,092 entitled “Multidimensional Imaging on a Curved Surface usingLenticular Lenses,” incorporated herein by reference in its entirety.

In one particular embodiment of the invention, the dimensional imagedisplay sheet comprises a game card having a first surface with one ormore lens arrays embossed thereon. The lens arrays lie below the planeof the first surface and are completely or at least partially containedwithin the borders of the game card. A printed image is printed on asecond, generally planar surface of the lens or a second substratepositioned under at least a portion of the lens array such that theprinted image is viewable through the lens array. The opticalcharacteristics of the lenses, i.e. shape, density, lens dimensions,etc. coupled with the printing technique used to print the image allowsfor a visual effect, such as three dimensionality and/or motion to beexperienced by the viewer when viewing the image through the lens array.One or more static images and/or aesthetics are printed on the planarportions of the first surface and/or the second surface and/or optionalsecond substrate such that it is viewable through the planar portions ofthe first surface.

The lens sheets, with or without printing, according to embodiments ofthe invention having a lens array below or flush with the planar surfaceof the lens sheet allows for a more uniform or consistent caliper as nolenses extend beyond the planar portions of the sheet. Lens sheets withrecessed or flush lens arrays can be stacked into a flat stack, or canbe rolled into a flat web, eliminating or reducing any bulging. Theoverall flatness of the sheet provides many advantages. For example, thelens sheets according to embodiments of the present invention can bemore easily printed than lens sheets of the prior art because the lenssheets present generally flat surfaces to a printing process with nolenses extending above the surface such that even pressure can bemaintained during printing. Further, the flat stacks or rolls are morereadily handled in autofeed processes. Finally, by incorporating thelens array within the body of the sheet, instead of extending from it,similar visual aesthetics as the prior art sheets can be accomplished atthinner calipers.

EXAMPLE

Referring to FIG. 16, caliper or thicknesses of two sheets 1600 (“SheetA” and “Sheet B” of cards 1602 having lens arrays 1604 were measured.Each sheet 1600 comprises APET. Each sheet 1600 includes sixty-threenested cards 1602. Sheets 1600 were made in a single run using anengraved or patterned cylinder. The APET was extruded onto the cylinder.The extrusion parameters were the same for both sheets.

Six measurements at points A-F were made on each card 1602 of each sheet1600. As shown in the cross-section, measurements A and D represent thethickness of the planar or gloss/gloss portions measured with a Mitutoyomicrometer, measurements B and C represent the thickness of the lensarray from base to lens peak also measured with a Mitutoyo micrometer,and measurements E and F represent the step height from the peak of thelenses of the lens array to the planar top surface or gloss area of thecard measured with a Starrett Step Micrometer.

The measurement results in Tables 2 and 3 below, and in the graphs ofFIGS. 17A-18B. The results include an individual measurement at eachlocation A-F for each card of each sheet. From this data, one cancalculate a number of statistics, such as, for example, but not limitedto sample mean, variance, standard deviation, or any of a number ofstatistical calculations as appropriate.

TABLE 2 Measurements for Sheet A (Inches) A B C D E F 1 0.0206 0.02 0.020.0201 0.0003 0.0001 2 0.0205 0.0197 0.0198 0.0203 0.0005 0.00025 30.0203 0.0197 0.0196 0.0205 0.0012 0.0003 4 0.0205 0.0197 0.0198 0.01940.0005 0.0003 5 0.0208 0.0197 0.0197 0.0201 0.00035 0.00085 6 0.02060.0197 0.0196 0.0202 0.0008 0.0001 7 0.0208 0.0198 0.0197 0.0202 0.000150.0001 8 0.0209 0.0197 0.0198 0.0203 0.0006 0.00005 9 0.0207 0.01970.0198 0.0205 0.0006 0.0008 10 0.0203 0.02 0.0196 0.0205 0.0001 0.000511 0.0202 0.02 0.02 0.0205 0.00005 0.0002 12 0.0203 0.0199 0.0199 0.02090.0002 0.00085 13 0.0204 0.0198 0.0198 0.0206 0.0005 0.0002 14 0.02030.0198 0.0197 0.02055 0.0008 0.0006 15 0.0203 0.0198 0.02 0.0206 0.00080.0011 16 0.0204 0.0198 0.0199 0.0206 0.00035 0.0008 17 0.0204 0.01980.0199 0.0197 0.0005 0.00095 18 0.0204 0.0199 0.0199 0.0207 0.000650.00085 19 0.0205 0.0198 0.0197 0.0202 0.0011 0.0005 20 0.0205 0.020.0198 0.0201 0.00145 0.0008 21 0.0207 0.0197 0.0196 0.0202 0.001050.0011 22 0.0204 0.0197 0.0197 0.0202 0.0011 0.001 23 0.0204 0.01970.0197 0.0201 0.0012 0.0005 24 0.0203 0.0198 0.0197 0.0203 0.00150.00075 25 0.0205 0.0198 0.0195 0.02 0.0009 0.00075 26 0.0196 0.01970.0197 0.0203 0.0001 0.00075 27 0.0207 0.0199 0.0197 0.02 0.001 0.000228 0.0204 0.0198 0.02 0.0206 0.0011 0.0005 29 0.0204 0.0198 0.02 0.02050.0011 0.0011 30 0.0203 0.0198 0.0198 0.0206 0.0011 0.001 31 0.0203 0.020.0198 0.0205 0.001 0.0011 32 0.0203 0.0198 0.0198 0.0206 0.001 0.0004533 0.0204 0.0199 0.02 0.0207 0.0005 0.00105 34 0.0203 0.0198 0.01980.0205 0.0008 0.00095 35 0.0202 0.0199 0.02 0.0207 0.00095 0.001 360.0206 0.0198 0.0197 0.0207 0.001 0.0012 37 0.0205 0.0197 0.0197 0.02040.0015 0.00155 38 0.0203 0.0196 0.0195 0.0206 0.0015 0.00135 39 0.02040.0196 0.0197 0.0206 0.0011 0.00085 40 0.0206 0.0196 0.0196 0.02050.0009 0.00075 41 0.0204 0.0197 0.0197 0.0204 0.0007 0.001 42 0.02040.0197 0.0197 0.0207 0.00075 0.0015 43 0.0204 0.0197 0.0197 0.02070.0015 0.001 44 0.0205 0.0198 0.0197 0.0206 0.00095 0.00095 45 0.02060.0197 0.0196 0.0207 0.0012 0.0011 46 0.0204 0.0196 0.0194 0.0203 0.00120.00095 47 0.0203 0.0195 0.0195 0.0204 0.001 0.0012 48 0.0207 0.01950.0194 0.0206 0.0011 0.0012 49 0.0205 0.0195 0.0194 0.0202 0.0008 0.001150 0.0205 0.0196 0.0194 0.0202 0.0005 0.001 51 0.0204 0.0196 0.01950.0203 0.0015 0.0015 52 0.0204 0.0196 0.0195 0.0203 0.00055 0.00075 530.0204 0.0197 0.0197 0.0204 0.0012 0.0011 54 0.0206 0.0197 0.0195 0.02060.0012 0.00135 55 0.0206 0.0197 0.0197 0.0205 0.001 0.0011 56 0.02050.0196 0.0196 0.0204 0.0011 0.00095 57 0.0205 0.0197 0.0196 0.02040.00155 0.00155 58 0.0205 0.0198 0.0197 0.0204 0.0011 0.00075 59 0.02050.0197 0.0196 0.0204 0.0009 0.0015 60 0.0205 0.0197 0.0197 0.02050.00095 0.0011 61 0.0206 0.0198 0.0198 0.0206 0.0008 0.0015 62 0.02070.02 0.0198 0.0205 0.00115 0.0005 63 0.021 0.0198 0.02 0.0205 0.00110.0011 Sample mean 0.0205 0.01975 0.01972 0.02041 0.00088 0.00085 (sheetA):

TABLE 3 Measurements for Sheet B (Inches) A B C D E F 1 0.0208 0.01970.0196 0.0202 0.0015 0.0003 2 0.0205 0.0197 0.0197 0.0202 0.0005 0.000153 0.0204 0.0196 0.0195 0.0203 0.0005 0.001 4 0.0207 0.0196 0.0197 0.02050.00085 0.00065 5 0.0208 0.0196 0.0197 0.0205 0.0006 0.0009 6 0.02060.0196 0.0197 0.0204 0.0011 0.0009 7 0.0205 0.0197 0.0197 0.0203 0.000850.00055 8 0.0205 0.0196 0.0196 0.0202 0.00075 0.0005 9 0.0205 0.01960.0195 0.0202 0.0015 0.0015 10 0.0202 0.0197 0.0198 0.02055 0.001 0.001111 0.0201 0.0196 0.0196 0.02055 0.00075 0.0016 12 0.0202 0.0198 0.01970.0206 0.001 0.00155 13 0.0204 0.02 0.0198 0.0208 0.0011 0.001 14 0.02020.0197 0.0198 0.0207 0.0011 0.0011 15 0.02025 0.0197 0.0197 0.02060.00065 0.0011 16 0.0202 0.01975 0.02 0.0207 0.00085 0.00175 17 0.02020.0197 0.01975 0.0209 0.0004 0.0015 18 0.0203 0.0197 0.0197 0.02060.0011 0.0011 19 0.02045 0.0197 0.0197 0.0199 0.00145 0.0006 20 0.02040.0197 0.0196 0.0201 0.0012 0.0011 21 0.0204 0.0198 0.0198 0.0205 0.00090.0009 22 0.0205 0.0197 0.0197 0.0205 0.0007 0.0008 23 0.0205 0.01970.01965 0.0202 0.0012 0.0008 24 0.0205 0.0195 0.0196 0.0205 0.001350.0009 25 0.0205 0.0197 0.0197 0.0204 0.0011 0.00065 26 0.0205 0.019650.01975 0.0201 0.00175 0.0002 27 0.0206 0.0197 0.0197 0.0201 0.0010.0011 28 0.0201 0.0196 0.0197 0.0205 0.0011 0.0011 29 0.0202 0.01950.0196 0.0204 0.00065 0.001 30 0.0204 0.0197 0.01975 0.0206 0.00110.0015 31 0.0203 0.0198 0.0198 0.0207 0.00035 0.00135 32 0.0202 0.01970.0197 0.0205 0.0009 0.0008 33 0.0202 0.01955 0.0196 0.0206 0.00060.0012 34 0.0202 0.0197 0.0197 0.0206 0.0011 0.0011 35 0.0203 0.01980.0198 0.0207 0.0005 0.001 36 0.0203 0.0196 0.0196 0.0206 0.0005 0.001137 0.0203 0.0195 0.0195 0.0206 0.001 0.0011 38 0.0203 0.0195 0.01950.0206 0.0008 0.0014 39 0.0204 0.0196 0.0196 0.0207 0.00075 0.0014 400.0203 0.0195 0.0197 0.0207 0.0006 0.0015 41 0.0203 0.01945 0.019450.0206 0.001 0.0011 42 0.0202 0.0194 0.0195 0.0207 0.0015 0.00155 430.0205 0.0194 0.0195 0.0207 0.0011 0.00085 44 0.0204 0.0195 0.01950.0206 0.0011 0.0015 45 0.0204 0.0195 0.0195 0.0207 0.00075 0.0011 460.0203 0.0194 0.0193 0.02025 0.00085 0.0012 47 0.0204 0.0194 0.01930.0204 0.00145 0.00085 48 0.0205 0.01945 0.0194 0.0205 0.001 0.001 490.0205 0.0195 0.0194 0.0205 0.001 0.001 50 0.0203 0.0193 0.0193 0.02030.00145 0.00075 51 0.0203 0.0194 0.0193 0.0203 0.001 0.0012 52 0.02040.0194 0.0194 0.0203 0.0008 0.0015 53 0.0204 0.0195 0.0194 0.02020.00035 0.00155 54 0.0205 0.0194 0.0194 0.0203 0.00135 0.0012 55 0.020750.01965 0.01965 0.02045 0.00155 0.0005 56 0.0205 0.0195 0.01955 0.020450.00085 0.0005 57 0.0206 0.0194 0.0196 0.0205 0.001 0.0011 58 0.02080.0197 0.0196 0.0206 0.00095 0.0012 59 0.02075 0.0194 0.0195 0.02040.0016 0.0011 60 0.0207 0.0194 0.0195 0.0204 0.0012 0.001 61 0.02060.0197 0.0196 0.0206 0.001 0.0015 62 0.0205 0.01960 0.0196 0.0206 0.00080.0005 63 0.02065 0.0195 0.0195 0.0204 0.0005 0.00095 Sample mean 0.02040.0196 0.0196 0.0205 0.0010 0.0010 (sheet B):

The invention may be embodied in other specific forms without departingfrom the essential attributes thereof; therefore, the illustratedembodiments should be considered in all respects as illustrative and notrestrictive.

What is claimed is:
 1. A lens sheet presenting a first surface and aplanar second surface, the lens sheet comprising: at least one lensarray formed in the first surface, the at least one lens array includinga plurality of lenses; at least one planar portion defined on the firstsurface, wherein a peak of each lens of the at least one lens array doesnot extend beyond the at least one planar portion of the first surface,wherein the at least one lens array is entirely bordered by at least oneplanar portion; and an image layer applied to the second surface,wherein the image layer is viewable through the first surface.
 2. Thelens sheet of claim 1, wherein the image layer is printed directly onthe second surface.
 3. The lens sheet of claim 1, wherein the imagelayer is printed on a separate substrate bonded to the second surface ofthe lens sheet.
 4. The lens sheet of claim 1, wherein the image layer isapplied below a lens array of the at least one lens array such that theimage layer is viewable through the lens array.
 5. The lens sheet ofclaim 1, further comprising a second image layer, wherein the secondimage layer is applied to the second surface below the at least oneplanar portion of the first surface such that the second image layer isviewable through the at least one planar portion.
 6. The lens sheet ofclaim 1, further comprising an image layer applied to the at least oneplanar portion of the first surface.
 7. The lens sheet of claim 1,wherein the lens sheet comprises a first lens array and a second lensarray, wherein lenses of the first lens array present a first lensheight and a first lens density, and wherein the lenses of the secondlens array present a second lens height and a second lens density.
 8. Acard comprising: a polymeric sheet having a first planar side, and asecond side including at least one lens array and at least one planarportion defined thereon, the at least one lens array comprising aplurality of lenses, wherein a peak of each lens array does not extendbeyond the at least one planar portion, and wherein the at least onelens array is entirely bordered by at least one planar portion; and animage layer applied to the first planar side of the polymeric sheet,wherein at least a portion of the image layer is positioned below a lensarray of the at least one lens array such that an image is viewablethrough the lens array to the second side.
 9. The card of claim 8,wherein an opaque layer is applied over at least a portion of the firstside.
 10. The card of claim 9, wherein the opaque layer extends over atleast a portion of the image layer.
 11. The card of claim 8, wherein anink layer is applied to one or more of the at least one planar portionson the second side.
 12. A method of forming a lens sheet, the methodcomprising: providing a polymeric sheet presenting a first surface and asecond surface; forming one or more lens arrays in an area of the firstsurface of the polymeric sheet, wherein remaining portions of the firstsurface comprise one or more planar portions, wherein each lens arraycomprises a plurality of lenses, wherein a peak of each lens does notextend above the one or more planar portions, and wherein the at leastone lens array is entirely bordered by at least one planar portion; andapplying at least one image layer to the second surface, wherein theimage layer is viewable through the first surface.
 13. The method ofclaim 12, wherein providing a polymeric sheet comprises extruding orcasting a polymeric material onto an engraved cylinder or platepatterned with a relief of the one or more lens arrays, and whereinforming the one or more lens arrays comprises embossing the polymericsheet with one or more lens arrays via the engraved cylinder or plate.14. A method of forming an imaged lens sheet, the method comprising:providing a lens sheet presenting a first surface and a planar secondsurface, the lens sheet including at least one lens array formed in thefirst surface, the at least one lens array including a plurality oflenses, and at least one planar portion defined on the first surface,wherein a peak of each lens of the at least one lens array does notextend beyond the at least one planar portion of the first surface, andwherein the at least one lens array is entirely bordered by at least oneplanar portion; and applying an image layer to the second surface of thepolymeric sheet, the image layer being viewable through the firstsurface.
 15. The method of claim 14, wherein at least a portion of theimage layer is positioned below at least one lens array of the one ormore lens arrays such that an image is viewable through the lens arrayto the first surface.
 16. The lens sheet of claim 14, wherein the imagelayer is applied to the second surface below the at least one planarportion of the first surface such that the image layer is viewablethrough the at least one planar portion.
 17. The lens sheet of claim 14,wherein the image layer is printed directly onto the second surface lenssheet.
 18. The lens sheet of claim 14, wherein the image layer isprinted on a separate substrate and bonded to the second surface of thelens sheet.
 19. The method of claim 14, further comprising: printing oneor more ink layers on one or more of the planar portions of the firstsurface of the lens sheet.
 20. The method of claim 14, furthercomprising: cutting the imaged lens sheet into a plurality of cards.